View source for Muscle atrophy

{{Infobox_Disease |
  Name           = {{PAGENAME}} |
  Image          = Muscle atrophy.jpg|
  Caption        = Muscle atrophy. <br> <small> [http://www.peir.net Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology] </small>|
}}
{{SI}}
{{CMG}} {{AB}} {{AE}} {{CZ}} {{LRO}}

'''Muscle atrophy''' refers to a decrease in the size of skeletal muscle, which occurs in a variety of settings. Atrophy may or may not be distinct from "[[sarcopenia]]", which is the loss of muscle seen in the aged.

When a muscle atrophies, it necessarily becomes weaker, since the ability to exert force is related to mass.

==Clinical settings of atrophy==
There are many diseases and conditions which cause a decrease in [[muscle]] mass, known as [[atrophy]], including: inactivity, as seen when a cast is put on a limb, or upon extended bedrest (which can occur during a prolonged illness); [[cachexia]] - which is a "body-wasting" syndrome that is a co-morbidity of [[cancer]] and [[Congestive Heart Failure]];  [[Chronic Obstructive Pulmonary Disease]]; burns, liver failure, etc. Other syndromes or conditions which can induce skeletal  muscle atrophy are  congestive heart disease, liver disease, and starvation.


==Causes==
<div style="-webkit-user-select: none;">

===Life Threatening Causes===
*[[Alcoholism]]
*[[Amyotrophic lateral sclerosis ]]
*[[Back tumor ]]
*[[Cerebrovascular accident]]
*[[Arachnoiditis]]
*[[Chondroblastoma ]]
*[[Chronic kidney disease ]]
*[[Embolism of great vessel]]
*[[Hepatoma ]]
*[[Herpes zoster]]
*[[Hip cancer ]]
*[[Hiv]]
*[[Ischemic palsy]]
*[[Malignancy]]
*[[Marasmus ]]
*[[Multiple sclerosis]]
*[[Neurodegeneration ]]
*[[Neurosyphilis ]]
*[[Parasitic infections]]
*[[Parkinson's disease]]
*[[Polio]]
*[[Polyarteritis nodosa]]
*[[Polymyositis]]
*[[Primary biliary cirrhosis ]]
*[[Primary lateral sclerosis ]]
*[[Rib tumor ]]
*[[Soft tissue hemorrhage]]
*[[Spinal cord tumor]]
*[[Spinal tumor]]
*[[Stroke]]
*[[Tuberculosis]]
===Common Causes===
*[[Adult progressive spinal muscular atrophy]]
*[[Adult sma ]]
*[[Athermoatous disease]]
*[[Back tumor ]]
*[[Becker's muscular dystrophy]]
*[[Cachexia]]
*[[Camurati-engelmann disease ]]
*[[Carpal tunnel syndrome]]
*[[Cerebellar ataxia]]
*[[Cervical spondylosis]]
*[[Chondroblastoma ]]
*[[Congenital muscular dystrophy ]]
*[[Disuse of limb]]
*[[Duchenne muscular dystrophy ]]
*[[Erb-goldflam ]]
*[[Erb's dystrophy ]]
*[[Fascioscapulohumeral]]
*[[Foix-alajouanine syndrome ]]
*[[Fosmn syndrome ]]
*[[Fukuyama type muscular dystrophy ]]
*[[Furukawa-takagi-nakao syndrome]]
*[[Gamstorp-wohlfart syndrome ]]
*[[Hematomyelia]]
*[[Hereditary inclusion body myopathy ]]
*[[Hereditary peripheral nervous disorder ]]
*[[Herniated disk]]
*[[Hip cancer ]]
*[[Hypertrophic neuropathy of dejerine-sottas ]]
*[[Immobility]]
*[[Immobilized fractures]]
*[[Inclusion body myopathy ]]
*[[Inclusion body myositis ]]
*[[Joint disuse ]]
*[[Joint inflammation]]
*[[Joint injuries]]
*[[Kuskokwim disease ]]
*[[Lambert-eaton myasthenic syndrome ]]
*[[Landouzy-dejerine muscular dystrophy ]]
*[[Legg-calve-perthes disease ]]
*[[Letterer-siwe disease ]]
*[[Limb-girdle muscular dystrophy type ]]
*[[Lumbar canal stenosis]]
*[[Lumbar spondylosis]]
*[[Meniscal tear]]
*[[Mitochondrial myopathy ]]
*[[Motor neuropathy ]]
*[[Muscle disuse]]
*[[Muscle injury]]
*[[Muscular dystrophy ]]
*[[Muscular fibrosis]]
*[[Muscular phosphorylase kinase deficiency ]]
*[[Myasthenia]]
*[[Myasthenic syndrome]]
*[[Myopathy ]]
*[[Nadh coq reductase]]
*[[Nemalin myopathy]]
*[[Nodulosis-arthropathy-osteolysis syndrome ]]
*[[Osteoarthritis]]
*[[Osteogenesis imperfecta ]]
*[[Paralysis of limbs]]
*[[Polymyositis]]
*[[Posterior column ataxia ]]
*[[Primary biliary cirrhosis ]]
*[[Primary lateral sclerosis ]]
*[[Primary muscle disease ]]
*[[Progressive spinal muscular atrophy ]]
*[[Prolapsed lumbar intervertebral disc]]
*[[Prolonged immobilization]]
*[[Proximal spinal muscular atrophy]]
*[[Salvioli syndrome ]]
*[[Soft tissue edema]]
*[[Soft tissue hemorrhage]]
*[[Spinal cord injury]]
*[[Spinal cord lesion]]
*[[Spinal cord tumor]]
*[[Spinal muscular atrophy ]]
*[[Spinal tumor]]
*[[Spinocerebellar ataxia ]]
*[[Subacute combined degeneration of the spinal cord]]
*[[Syphilitic amyotrophy]]
*[[Syringomyelia]]
*[[Thoracic outlet syndrome ]]
*[[Vacuolar myopathy ]]
*[[Volkmann's contracture]]
*[[Welander distal myopathy]]

===Causes by Organ System===
{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" |'''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | [[Athermoatous disease]],  [[Buerger's disease]],  [[Cerebrovascular accident]],  [[Embolism of great vessel]],  [[Foix-alajouanine syndrome ]],  [[Ischemic palsy]],  [[Lipidosis with triglyceride storage disease ]],  [[Lumbar canal stenosis]],  [[Meningovascular malformations]],  [[Stroke]],  [[Thrombosis of great vessel]],  [[Vascular disease]],  [[Volkmann's contracture]]
|-
|bgcolor="LightSteelBlue"| '''Chemical/Poisoning'''
|bgcolor="Beige"| [[Alcoholism]],  [[Lupine poisoning ]]
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| [[Burns]],  [[Dermatomyositis ]],  [[Leiner disease ]],  [[Leprosy ]],  [[Letterer-siwe disease ]],  [[Ulerythema ophryogenesis ]]
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Cocaine]],  [[Drug use]],  [[Hexane ]],  [[Medications]],  [[Penicillamine]],  [[Pergolide]],  [[Prolonged steroid therapy]],  [[Statins]],  [[Steroid use]]
|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Adrenal dysfunction]],  [[Carnitine deficiency]],  [[Decreased appetite]],  [[Endocrine disorders]],  [[Glycogen storage myopathy]],  [[Hypercortisolism]],  [[Hyperthyroidism]],  [[Hypothyroidism]],  [[Kwashiorkor]],  [[Sandhoff disease ]],  [[Thyroid disease]],  [[Thyroid dysfunction]]
|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| [[Bed rest]]
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| [[Andersen disease ]],  [[Andrade's syndrome ]],  [[Banti syndrome ]],  [[Bard-pic syndrome ]],  [[Chronic diarrhoea]],  [[Glycogen storage myopathy]],  [[Hepatoma ]],  [[Kwashiorkor]],  [[Malabsorption syndrome]],  [[Mitochondrial neurogastrointestinal encephalopathy syndrome ]],  [[Rib tumor ]],  [[Tropical sprue]],  [[Type iv glycogen storage disease ]]
|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| [[Allan-herndon-dudley syndrome ]],  [[Alves castelo dos santos syndrome ]],  [[Andersen disease ]],  [[Andrade's syndrome ]],  [[Arthrogryposis]],  [[Bethlem myopathy ]],  [[Bruyn-scheltens syndrome]],  [[Camurati-engelmann disease ]],  [[Charcot-marie-tooth disease]],  [[Charlevoix-saguenay spastic ataxia]],  [[Coenzyme q 10 (coq10) deficiency ]],  [[Complex 1 mitochondrial respiratory chain deficiency ]],  [[Congenital disorder of glycosylation]],  [[Cutler syndrome ]],  [[Cytoplasmic body myopathy ]],  [[Dyskeratosis congenita of zinsser-cole-engman ]],  [[Dystrophia myotonica 1 ]],  [[Emery-dreifuss syndrome ]],  [[Facwa syndrome ]],  [[Fascioscapulohumeral]],  [[Friedreich ataxia ]],  [[Fukuyama type muscular dystrophy ]],  [[Furukawa-takagi-nakao syndrome]],  [[Gamstorp-wohlfart syndrome ]],  [[Gangliosidosis]],  [[Jequier-kozlowski-skeletal dysplasia ]],  [[Kuskokwim disease ]],  [[Levine-critchley syndrome ]],  [[Madsam ]],  [[Marinesco-sjogren syndrome ]],  [[Mc leod neuroacanthocytosis syndrome ]],  [[Minicore disease ]],  [[Miyoshi myopathy ]],  [[Morse-rawnsley-sargent syndrome ]],  [[Multicentric osteolysis]],  [[Multiminicore disease ]],  [[Myotonic dystrophy]],  [[Nadh coq reductase]],  [[Neu-laxova syndrome]],  [[Nodulosis-arthropathy-osteolysis syndrome ]],  [[Oculopharyngeal dystrophy]],  [[Osteogenesis imperfecta ]],  [[Palmoplantar keratoderma ]],  [[Pantothenate kinase-associated neurodegeneration ]],  [[Parsonage turner syndrome]],  [[Passos-bueno syndrome ]],  [[Pontocerebellar hypoplasia ]],  [[Richards-rundle syndrome ]],  [[Rud syndrome ]],  [[Salvioli syndrome ]],  [[Schwartz-jampel syndrome ]],  [[Scleroatonic muscular dystrophy ]],  [[Short chain acyl coa dehydrogenase deficiency]],  [[Singleton-merten syndrome ]],  [[Small syndrome ]],  [[Storm syndrome ]],  [[Syringomyelia]],  [[Tay sachs ]],  [[Troyer syndrome]],  [[Ulerythema ophryogenesis ]],  [[Wieacker syndrome]],  [[Wieacker-wolff syndrome]],  [[Wilson's disease ]],  [[X-linked mental retardation]]
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| [[Diabetes]],  [[Lipidosis with triglyceride storage disease ]],  [[Metachromatic leukodystrophy ]],  [[Soft tissue hemorrhage]],  [[Type iv glycogen storage disease ]],  [[Undiagnosed diabetes mellitus]]
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| [[Surgical ligation of major vessel]]
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Aids wasting syndrome ]],  [[Bacterial infections]],  [[Bovine spongiform encephalopathy ]],  [[Coxsacki b virus]],  [[Glandular fever]],  [[Herpes zoster]],  [[Hiv]],  [[Hookworm infestation]],  [[Intestinal capillariasis ]],  [[Malaria]],  [[Mycobacterium kansasii ]],  [[Neurosyphilis ]],  [[Parasitic infections]],  [[Polio]],  [[Post-polio syndrome]],  [[Schistosomiasis]],  [[Thyrotoxicosis]],  [[Toxoplasmosis]],  [[Trichinosis]],  [[Tropical sprue]],  [[Tuberculosis]],  [[Viral infections]],  [[Wasting syndrome ]]
|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal/Orthopedic'''
|bgcolor="Beige"| [[Adult progressive spinal muscular atrophy]],  [[Adult sma ]],  [[Athermoatous disease]],  [[Back tumor ]],  [[Becker's muscular dystrophy]],  [[Cachexia]],  [[Camurati-engelmann disease ]],  [[Carpal tunnel syndrome]],  [[Cerebellar ataxia]],  [[Cervical spondylosis]],  [[Chondroblastoma ]],  [[Congenital muscular dystrophy ]],  [[Disuse of limb]],  [[Duchenne muscular dystrophy ]],  [[Erb-goldflam ]],  [[Erb's dystrophy ]],  [[Fascioscapulohumeral]],  [[Foix-alajouanine syndrome ]],  [[Fosmn syndrome ]],  [[Fukuyama type muscular dystrophy ]],  [[Furukawa-takagi-nakao syndrome]],  [[Gamstorp-wohlfart syndrome ]],  [[Hematomyelia]],  [[Hereditary inclusion body myopathy ]],  [[Hereditary peripheral nervous disorder ]],  [[Herniated disk]],  [[Hip cancer ]],  [[Hypertrophic neuropathy of dejerine-sottas ]],  [[Immobility]],  [[Immobilized fractures]],  [[Inclusion body myopathy ]],  [[Inclusion body myositis ]],  [[Joint disuse ]],  [[Joint inflammation]],  [[Joint injuries]],  [[Kuskokwim disease ]],  [[Lambert-eaton myasthenic syndrome ]],  [[Landouzy-dejerine muscular dystrophy ]],  [[Legg-calve-perthes disease ]],  [[Letterer-siwe disease ]],  [[Limb-girdle muscular dystrophy type ]],  [[Lumbar canal stenosis]],  [[Lumbar spondylosis]],  [[Meniscal tear]],  [[Mitochondrial myopathy ]],  [[Motor neuropathy ]],  [[Muscle disuse]],  [[Muscle injury]],  [[Muscular dystrophy ]],  [[Muscular fibrosis]],  [[Muscular phosphorylase kinase deficiency ]],  [[Myasthenia]],  [[Myasthenic syndrome]],  [[Myopathy ]],  [[Nadh coq reductase]],  [[Nemalin myopathy]],  [[Nodulosis-arthropathy-osteolysis syndrome ]],  [[Osteoarthritis]],  [[Osteogenesis imperfecta ]],  [[Paralysis of limbs]],  [[Polymyositis]],  [[Posterior column ataxia ]],  [[Primary biliary cirrhosis ]],  [[Primary lateral sclerosis ]],  [[Primary muscle disease ]],  [[Progressive spinal muscular atrophy ]],  [[Prolapsed lumbar intervertebral disc]],  [[Prolonged immobilization]],  [[Proximal spinal muscular atrophy]],  [[Salvioli syndrome ]],  [[Soft tissue edema]],  [[Soft tissue hemorrhage]],  [[Spinal cord injury]],  [[Spinal cord lesion]],  [[Spinal cord tumor]],  [[Spinal muscular atrophy ]],  [[Spinal tumor]],  [[Spinocerebellar ataxia ]],  [[Subacute combined degeneration of the spinal cord]],  [[Syphilitic amyotrophy]],  [[Syringomyelia]],  [[Thoracic outlet syndrome ]],  [[Vacuolar myopathy ]],  [[Volkmann's contracture]],  [[Welander distal myopathy]]
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| [[Adult sma ]],  [[Alcoholic neuropathy ]],  [[Amyotrophic lateral sclerosis ]],  [[Arachnoiditis ]],  [[Ataxia]],  [[Balo's concentric sclerosis ]],  [[Bovine spongiform encephalopathy ]],  [[Cerebellar ataxia]],  [[Cerebrovascular accident]],  [[Charcot-marie-tooth disease]],  [[Creutzfeldt-jakob disease]],  [[Cytoplasmic body myopathy ]],  [[Damage to nerve supplying muscle]],  [[Decreased appetite]],  [[Degenerative motor system disease ]],  [[Diabetic neuropathy]],  [[Erb-goldflam ]],  [[Erb's dystrophy ]],  [[Fosmn syndrome ]],  [[Friedreich ataxia ]],  [[Generalized myasthenia gravis ]],  [[Hematomyelia]],  [[Hereditary peripheral nervous disorder ]],  [[Hypertrophic neuropathy of dejerine-sottas ]],  [[Inclusion body myopathy ]],  [[Inclusion body myositis ]],  [[Intercostal neuralgia ]],  [[Ischemic palsy]],  [[Lower motor neurone lesion]],  [[Madsam ]],  [[Meningovascular malformations]],  [[Mental retardation]],  [[Mitochondrial encephalomyopathy ]],  [[Mitochondrial neurogastrointestinal encephalopathy syndrome ]],  [[Motor neurone disease]],  [[Motor neuropathy ]],  [[Multifocal motor neuropathy ]],  [[Multiple sclerosis]],  [[Nerve compression]],  [[Nerve entrapment ]],  [[Nerve injury]],  [[Neurodegeneration ]],  [[Neuropathy ]],  [[Neurosyphilis ]],  [[Olivopontocerebellar atrophy i ]],  [[Paralysis of limbs]],  [[Parkinson's disease]],  [[Parsonage turner syndrome]],  [[Peripheral nerve trauma]],  [[Peripheral neuritis ]],  [[Peripheral neuropathy]],  [[Polyradiculoneuropathy ]],  [[Pontocerebellar hypoplasia ]],  [[Posterior column ataxia ]],  [[Primary biliary cirrhosis ]],  [[Primary lateral sclerosis ]],  [[Primary muscle disease ]],  [[Progressive spinal muscular atrophy ]],  [[Prolapsed lumbar intervertebral disc]],  [[Prolonged immobilization]],  [[Proximal spinal muscular atrophy]],  [[Radiculopathy]],  [[Reflex sympathetic dystrophy syndrome]],  [[Small syndrome ]],  [[Spinal bulbar motor neuropathy ]],  [[Spinocerebellar ataxia ]],  [[Thyrocerebral-retinal syndrome ]],  [[X-linked mental retardation]]
|-
|-bgcolor="LightSteelBlue"
| '''Nutritional/Metabolic'''
|bgcolor="Beige"| [[Diabetes]],  [[Diabetic neuropathy]],  [[Malnutrition]],  [[Marasmus ]],  [[Muscular phosphorylase kinase deficiency ]],  [[Obal syndrome ]],  [[Protein deficiency]],  [[Undiagnosed diabetes mellitus]]
|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| [[Back tumor ]],  [[Chondroblastoma ]],  [[Hepatoma ]],  [[Hip cancer ]],  [[Intramedullary astrocytoma]],  [[Intramedullary ependymoma]],  [[Malignancy]],  [[Rib tumor ]],  [[Spinal cord tumor]],  [[Spinal tumor]]
|-
|-bgcolor="LightSteelBlue"
| '''Ophthalmologic'''
|bgcolor="Beige"| [[Incontinentia pigmenti ]],  [[Intestinal capillariasis ]],  [[Obal syndrome ]],  [[Thyrocerebral-retinal syndrome ]]
|-
|-bgcolor="LightSteelBlue"
| '''Overdose/Toxicity'''
|bgcolor="Beige"| [[Alcoholic neuropathy ]],  [[Alcoholism]]
|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Anorexia nervosa ]]
|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| [[Embolism of great vessel]],  [[Sarcoidosis]],  [[Tuberculosis]]
|-
|-bgcolor="LightSteelBlue"
| '''Renal/Electrolyte'''
|bgcolor="Beige"| [[Chronic kidney disease ]],  [[Lightwood-albright syndrome]],  [[Nephrotic syndrome ]]
|-
|-bgcolor="LightSteelBlue"
| '''Rheumatology/Immunology/Allergy'''
|bgcolor="Beige"| [[Ankylosis ]],  [[Arthritis]],  [[Arthrogryposis]],  [[Buerger's disease]],  [[Cachexia]],  [[Carpal tunnel syndrome]],  [[Cervical spondylosis]],  [[Cushing's disease]],  [[Dermatomyositis ]],  [[Juvenile rheumatoid arthritis ]],  [[Lambert-eaton myasthenic syndrome ]],  [[Landouzy-dejerine muscular dystrophy ]],  [[Leprosy ]],  [[Lumbar spondylosis]],  [[Muscular fibrosis]],  [[Osteoarthritis]],  [[Polyarteritis nodosa]],  [[Rheumatoid arthritis]],  [[Sarcoidosis]],  [[Wohlwill-andrade syndrome ]]
|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| [[Aids wasting syndrome ]],  [[Hiv]],  [[Syphilitic amyotrophy]],  [[Wasting syndrome ]]
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| [[Burns]],  [[Damage to nerve supplying muscle]],  [[Herniated disk]],  [[Immobilized fractures]],  [[Joint injuries]],  [[Meniscal tear]],  [[Muscle injury]],  [[Nerve compression]],  [[Nerve entrapment ]],  [[Nerve injury]],  [[Peripheral nerve trauma]],  [[Spinal cord injury]],  [[Spinal cord lesion]],  [[Subacute combined degeneration of the spinal cord]],  [[Tourniquet paralysis]]
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| [[Multiple system atrophy ]],  [[Old age]]
|-
|}

===Causes in Alphabetical Order===
{{columns-list|
*[[Acanthocytosis ]]
*[[Acyl-coa dehydrogenase]]
*[[Addison's disease]]
*[[Adrenal dysfunction]]
*[[Adult progressive spinal muscular atrophy]]
*[[Adult sma ]]
*[[Aids wasting syndrome ]]
*[[Alcoholic neuropathy ]]
*[[Alcoholism]]
*[[Allan-herndon-dudley syndrome ]]
*[[Alves castelo dos santos syndrome ]]
*[[Amyotrophic lateral sclerosis ]]
*[[Andersen disease ]]
*[[Andrade's syndrome ]]
*[[Ankylosis ]]
*[[Anorexia nervosa ]]
*[[Arachnoiditis ]]
*[[Arthritis]]
*[[Arthrogryposis]]
*[[Ataxia]]
*[[Athermoatous disease]]
*[[Back tumor ]]
*[[Bacterial infections]]
*[[Balo's concentric sclerosis ]]
*[[Banti syndrome ]]
*[[Bard-pic syndrome ]]
*[[Becker's muscular dystrophy]]
*[[Bed rest]]
*[[Bethlem myopathy ]]
*[[Bovine spongiform encephalopathy ]]
*[[Bruyn-scheltens syndrome]]
*[[Buerger's disease]]
*[[Burns]]
*[[Cachexia]]
*[[Camurati-engelmann disease ]]
*[[Carnitine deficiency]]
*[[Carpal tunnel syndrome]]
*[[Cerebellar ataxia]]
*[[Cerebrovascular accident]]
*[[Cervical spondylosis]]
*[[Charcot-marie-tooth disease]]
*[[Charlevoix-saguenay spastic ataxia]]
*[[Chondroblastoma ]]
*[[Chronic diarrhoea]]
*[[Chronic kidney disease ]]
*[[Cocaine]]
*[[Coenzyme q 10 (coq10) deficiency ]]
*[[Complex 1 mitochondrial respiratory chain deficiency ]]
*[[Congenital disorder of glycosylation]]
*[[Congenital muscular dystrophy ]]
*[[Coxsacki b virus]]
*[[Creutzfeldt-jakob disease]]
*[[Cushing's disease]]
*[[Cutler syndrome ]]
*[[Cytoplasmic body myopathy ]]
*[[Damage to nerve supplying muscle]]
*[[Decreased appetite]]
*[[Degenerative motor system disease ]]
*[[Dermatomyositis ]]
*[[Diabetes]]
*[[Diabetic neuropathy]]
*[[Disuse of limb]]
*[[Drug use]]
*[[Duchenne muscular dystrophy ]]
*[[Dyskeratosis congenita of zinsser-cole-engman ]]
*[[Dystrophia myotonica 1 ]]
*[[Embolism of great vessel]]
*[[Emery-dreifuss syndrome ]]
*[[Endocrine disorders]]
*[[Erb-goldflam ]]
*[[Erb's dystrophy ]]
*[[Facwa syndrome ]]
*[[Fascioscapulohumeral]]
*[[Foix-alajouanine syndrome ]]
*[[Fosmn syndrome ]]
*[[Friedreich ataxia ]]
*[[Fukuyama type muscular dystrophy ]]
*[[Furukawa-takagi-nakao syndrome]]
*[[Gamstorp-wohlfart syndrome ]]
*[[Gangliosidosis]]
*[[Generalized myasthenia gravis ]]
*[[Glandular fever]]
*[[Glycogen storage myopathy]]
*[[Hematomyelia]]
*[[Hepatoma ]]
*[[Hereditary inclusion body myopathy ]]
*[[Hereditary peripheral nervous disorder ]]
*[[Herniated disk]]
*[[Herpes zoster]]
*[[Hexane ]]
*[[Hip cancer ]]
*[[Hiv]]
*[[Hookworm infestation]]
*[[Hypercortisolism]]
*[[Hyperthyroidism]]
*[[Hypertrophic neuropathy of dejerine-sottas ]]
*[[Hypothyroidism]]
*[[Immobility]]
*[[Immobilized fractures]]
*[[Inclusion body myopathy ]]
*[[Inclusion body myositis ]]
*[[Incontinentia pigmenti ]]
*[[Intercostal neuralgia ]]
*[[Intestinal capillariasis ]]
*[[Intramedullary astrocytoma]]
*[[Intramedullary ependymoma]]
*[[Ischemic palsy]]
*[[Jequier-kozlowski-skeletal dysplasia ]]
*[[Joint disuse ]]
*[[Joint inflammation]]
*[[Joint injuries]]
*[[Juvenile rheumatoid arthritis ]]
*[[Kuskokwim disease ]]
*[[Kwashiorkor]]
*[[Lambert-eaton myasthenic syndrome ]]
*[[Landouzy-dejerine muscular dystrophy ]]
*[[Legg-calve-perthes disease ]]
*[[Leiner disease ]]
*[[Leprosy ]]
*[[Letterer-siwe disease ]]
*[[Levine-critchley syndrome ]]
*[[Lightwood-albright syndrome]]
*[[Limb-girdle muscular dystrophy type ]]
*[[Lipidosis with triglyceride storage disease ]]
*[[Lower motor neurone lesion]]
*[[Lumbar canal stenosis]]
*[[Lumbar spondylosis]]
*[[Lupine poisoning ]]
*[[Madsam ]]
*[[Malabsorption syndrome]]
*[[Malaria]]
*[[Malignancy]]
*[[Malnutrition]]
*[[Marasmus ]]
*[[Marinesco-sjogren syndrome ]]
*[[Mc leod neuroacanthocytosis syndrome ]]
*[[Medications]]
*[[Meningovascular malformations]]
*[[Meniscal tear]]
*[[Mental retardation]]
*[[Metachromatic leukodystrophy ]]
*[[Minicore disease ]]
*[[Mitochondrial encephalomyopathy ]]
*[[Mitochondrial myopathy ]]
*[[Mitochondrial neurogastrointestinal encephalopathy syndrome ]]
*[[Miyoshi myopathy ]]
*[[Morse-rawnsley-sargent syndrome ]]
*[[Motor neurone disease]]
*[[Motor neuropathy ]]
*[[Multicentric osteolysis]]
*[[Multifocal motor neuropathy ]]
*[[Multiminicore disease ]]
*[[Multiple sclerosis]]
*[[Multiple system atrophy ]]
*[[Muscle disuse]]
*[[Muscle injury]]
*[[Muscular dystrophy ]]
*[[Muscular fibrosis]]
*[[Muscular phosphorylase kinase deficiency ]]
*[[Myasthenia]]
*[[Myasthenic syndrome]]
*[[Mycobacterium kansasii ]]
*[[Myopathy ]]
*[[Myotonic dystrophy]]
*[[Nadh coq reductase]]
*[[Nemalin myopathy]]
*[[Nephrotic syndrome ]]
*[[Nerve compression]]
*[[Nerve entrapment ]]
*[[Nerve injury]]
*[[Neu-laxova syndrome]]
*[[Neurodegeneration ]]
*[[Neuropathy ]]
*[[Neurosyphilis ]]
*[[Nodulosis-arthropathy-osteolysis syndrome ]]
*[[Obal syndrome ]]
*[[Oculopharyngeal dystrophy]]
*[[Old age]]
*[[Olivopontocerebellar atrophy i ]]
*[[Osteoarthritis]]
*[[Osteogenesis imperfecta ]]
*[[Palmoplantar keratoderma ]]
*[[Pantothenate kinase-associated neurodegeneration ]]
*[[Paralysis of limbs]]
*[[Parasitic infections]]
*[[Parkinson disease]]
*[[Parkinson's disease]]
*[[Parsonage turner syndrome]]
*[[Passos-bueno syndrome ]]
*[[Penicillamine]]
*[[Pergolide]]
*[[Peripheral nerve trauma]]
*[[Peripheral neuritis ]]
*[[Peripheral neuropathy]]
*[[Polio]]
*[[Polyarteritis nodosa]]
*[[Polymyositis]]
*[[Polyradiculoneuropathy ]]
*[[Pontocerebellar hypoplasia ]]
*[[Posterior column ataxia ]]
*[[Post-polio syndrome]]
*[[Primary biliary cirrhosis ]]
*[[Primary lateral sclerosis ]]
*[[Primary muscle disease ]]
*[[Progressive spinal muscular atrophy ]]
*[[Prolapsed lumbar intervertebral disc]]
*[[Prolonged immobilization]]
*[[Prolonged steroid therapy]]
*[[Protein deficiency]]
*[[Proximal spinal muscular atrophy]]
*[[Radiculopathy]]
*[[Reflex sympathetic dystrophy syndrome]]
*[[Rheumatoid arthritis]]
*[[Rib tumor ]]
*[[Richards-rundle syndrome ]]
*[[Rud syndrome ]]
*[[Salvioli syndrome ]]
*[[Sandhoff disease ]]
*[[Sarcoidosis]]
*[[Schistosomiasis]]
*[[Schwartz-jampel syndrome ]]
*[[Scleroatonic muscular dystrophy ]]
*[[Short chain acyl coa dehydrogenase deficiency]]
*[[Singleton-merten syndrome ]]
*[[Small syndrome ]]
*[[Soft tissue edema]]
*[[Soft tissue hemorrhage]]
*[[Spinal bulbar motor neuropathy ]]
*[[Spinal cord injury]]
*[[Spinal cord lesion]]
*[[Spinal cord tumor]]
*[[Spinal muscular atrophy ]]
*[[Spinal tumor]]
*[[Spinocerebellar ataxia ]]
*[[Statins]]
*[[Steroid use]]
*[[Storm syndrome ]]
*[[Stroke]]
*[[Subacute combined degeneration of the spinal cord]]
*[[Surgical ligation of major vessel]]
*[[Syphilitic amyotrophy]]
*[[Syringomyelia]]
*[[Tay sachs ]]
*[[Thoracic outlet syndrome ]]
*[[Thrombosis of great vessel]]
*[[Thyrocerebral-retinal syndrome ]]
*[[Thyroid disease]]
*[[Thyroid dysfunction]]
*[[Thyrotoxicosis]]
*[[Tourniquet paralysis]]
*[[Toxoplasmosis]]
*[[Trichinosis]]
*[[Tropical sprue]]
*[[Troyer syndrome]]
*[[Tuberculosis]]
*[[Type iv glycogen storage disease ]]
*[[Ulerythema ophryogenesis ]]
*[[Undiagnosed diabetes mellitus]]
*[[Vacuolar myopathy ]]
*[[Vascular disease]]
*[[Viral infections]]
*[[Volkmann's contracture]]
*[[Wasting syndrome ]]
*[[Welander distal myopathy]]
*[[Wieacker syndrome]]
*[[Wieacker-wolff syndrome]]
*[[Wilson's disease ]]
*[[Wohlwill-andrade syndrome ]]
*[[X-linked mental retardation]]
}}
</div>

==Other muscles diseases, distinct from atrophy==
During aging, there is a gradual decrease in the ability to maintain skeletal muscle function and mass.  This condition is called "[[sarcopenia]]".  The exact cause of [[sarcopenia]] is unknown, but it may be due to a combination of the gradual failure in the "[[satellite cells]]" which help to regenerate skeletal muscle fibers, and a decrease in sensitivity to or the availability of critical secreted [[growth factors]] which are necessary to maintain muscle mass and satellite cell survival.

In addition to the simple loss of muscle mass ([[atrophy]]), or the age-related decrease in muscle function ([[sarcopenia]]), there are other diseases which may be caused by structural defects in the muscle ([[muscular dystrophy]]), or by inflammatory reactions in the body directed against muscle (the myopathies).

==Pathophysiology==
Muscle atrophy occurs by a change in the normal balance between protein synthesis and protein degradation.  During atrophy, there is a down-regulation of protein synthesis pathways, and an activation of protein breakdown pathways.  The particular protein degradation pathway which seems to be responsible for much of the muscle loss seen in a muscle undergoing atrophy is the "ATP-dependent, [[ubiquitin]]/[[proteasome]] pathway.  In this system, particular proteins are targeted for destruction by the ligation of at least four copies of a small peptide called [[ubiquitin]] onto a substrate protein.  When a substrate is thus "poly-ubiquitinated", it is targeted for destruction by the [[proteasome]].  Particular enzymes in the ubiquitin/proteasome pathway allow ubiquitination to be directed to some proteins but not others - specificity is gained by coupling targeted proteins to  an "E3 [[ubiquitin ligase]]".  Each  E3 [[ubiquitin ligase]] binds to a particular set of substrates, causing their ubiquitination.

==Diagnostic Findings==

<div align="left">
<gallery heights="175" widths="175">
Image:extremities_left_thenar_wasting.jpg|Muscle Wasting Left Hand: Atrophic flattening most prominently seen in the  thenar and hypothenar muscles, resulting from generalized denervation.
</gallery>
</div>

==Potential treatment==
Muscle atrophy can be opposed by the signaling pathways which induce muscle hypertrophy, or an increase in muscle size.  Therefore one way in which [[exercise]] induces an increase in muscle mass is to downregulate the pathways which have the opposite effect.

==See also==
*[[Muscle weakness]]
*Muscle dystrophy

==External links==
* {{MeshName|Muscular+atrophy}}

{{Geriatrics}}


[[Category:Geriatrics]]
[[Category:Physiology]]
[[Category:Medical conditions related to obesity]]
[[Category:Diabetes]]
[[Category:Gross pathology]]
[[Category:Rehabilitation medicine]]
[[Category:Medical signs]]
[[Category:Signs and symptoms]]
{{WH}}
{{WS}}